SENSORS
MICRO-VIBRATION
ACCELEROMETERS
PERFORM IN A COLD
SPACE SIMULATOR
The development of a pioneering space telescope required the proving
of an accelerometer’s reliability in an extremely harsh environment
// HENK VAN WEERS, MARTIN EGGENS, HEINO SMIT AND MARINE DUMONT
Scientists looking for breakthroughs in
astrophysical, atmospheric and
exoplanetary research need ever more
sensitive space telescopes and satellites.
The SRON Netherlands Institute for Space
Research develops pioneering technology
and advanced space instruments. A strong
focus lies on cryogenic detector systems,
currently the only systems reaching the
extreme sensitivity that are required for
future space applications.
SRON is involved in the development of
the scientific X-IFU instrument (X-ray
Integral Field Unit) for the European Space
Agency’s (ESA) Athena X-ray space
observatory, which is planned for launch
in the early 2030s. Athena will study hot
and energetic clusters of galaxies, black
holes and exploding stars. X-IFU will be at
the focal point of Athena and uses highly
sensitive microcalorimeters, based on
Transition Edge Sensors (TES), for
measuring the tiny amount of heat
released when an X-ray is absorbed.
SRON is developing the Focal Plane
Assembly (FPA), in which the TES
detectors are cooled at 50 milliKelvin. The
TES arrays are mechanically suspended to
a structure at 2 Kelvin, using an
intermediate temperature level of
300 milliKelvin.
TESTING THE ACCELEROMETER
NEAR ABSOLUTE ZERO
The TES detectors and FPAs are being
tested and calibrated in dedicated vacuum
chambers in SRON’s labs, which mimic the
thermal environment of the spacecraft.
The current mechanical design of X-IFU’s
FPA including Kevlar suspension and is
based on heritage and analyses.
However, the influence of micro
144 SHOWCASE 2020 \\ AEROSPACETESTINGINTERNATIONAL.COM
1 // 3D-model of a partial
FPA to indicate the
different temperature levels
and thermal suspension
2 // PiezoStar Cryo Temp
Accelerometer
3 // Schematic overview
of the test cryostat and
test setup
1
2
vibrations on temperature stability needed
further understanding. SRON therefore
wanted to measure the relationship
between micro-vibration levels and
fluctuations at operational temperatures
down to 3 Kelvin. They required a small,
low mass and low dissipation
accelerometer. The Kistler accelerometer
8712B5D0CB meets all of these
requirements, but to find out how the
sensor behaves at very low temperatures
SRON researchers tested it in their
cryogenic test environment, with the kind
support of Kistler.
The goals of the research were to
pinpoint how the accelerometer operates at
very low temperatures, to test the
robustness and to indicate the sensitivity,
noise and dissipation at different cryogenic
temperatures.
3
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